1. Field of the Invention
The present invention relates generally to the field of medication administration devices. More specifically the present invention relates to a flow rate selection valve such as for placement between a piercing tube structure referred to as a spike structure for piercing and draining solution from a standard intravenous bag and a drip chamber which opens into an intravenous line. The valve includes a gate cylinder having at least two flow rate determining passageways and passing diametrically through the gate cylinder at orientations angularly displaced from each other, and having a rotation engagement structure preferably in the form of a finger grip structure at one cylinder end for gate cylinder rotation; and which further includes a valve housing having a flow passageway and having a cylinder receiving bore intersecting and preferably perpendicular to the flow passageway into which the gate cylinder is rotatably and sealingly mounted, dividing the flow passageway into a passageway inlet end and a passageway outlet end. A passageway registration barrier extends across the passageway outlet end and sealingly fits partly around and against the gate cylinder and has several flow ports, each flow port corresponding to and registering with one of the flow rate determining passageways such that only one flow port registers with one rate determining passageway at a time.
The flow ports have different minimum diameters so that selection of the rate determining passageway and its corresponding flow port selects one of several available flow rates through the valve. Alternatively, the flow rate determining passageways have different minimum diameters, once again so that selection of a given flow rate determining passageway selects one of several available flow rates through the valve.
The standard spike structure is understood to include a tubular inlet passageway having a bag piercing tube upper end, a tubular spike structure body and a spike structure outlet port surrounded by a downwardly opening spike structure perimeter slot. The standard drip chamber is understood to include a tubular chamber side wall with a side wall upper end terminating in a side wall upper rim defining a drip chamber inlet opening, and a side wall lower end terminating in a chamber bottom wall with a drip chamber outlet opening encircled by a downwardly extending intravenous line fitting nozzle.
2. Description of the Prior Art
There are numerous tubular liquid delivering lines used in medical treatment, one of which is the intravenous line for delivering a solution from an intravenous bag to a catheter inserted into a vein of a patient. An intravenous bag piercing tube structure or spike structure pierces the intravenous bag and opens downwardly into a transparent drip chamber which in turn opens into the intravenous line. A problem with these prior intravenous assemblies has been that no suitable provision has been made for precisely selecting one of several desired flow rates from for a solution passing from the intravenous bag into the line.
It is thus an object of the present invention to provide a flow rate selection valve for liquid deliver lines such as intravenous lines which provides several different, precise and individually selectable flow rates.
It is another object of the present invention to provide such a flow rate selection valve having an inlet end which sealingly fits to a standard spike structure and an outlet end which sealingly fits to a standard drip chamber to regulate flow from the spike structure to the drip chamber.
It is still another object of the present invention to provide such a flow rate selection valve which is suitable for a wide variety of liquid delivery applications.
It is finally an object of the present invention to provide such a flow rate selection valve which is safe, reliable, inexpensive to manufacture and easy to connect and use.